Lobrathium (Lobrathium) nigripenne, Assing, 2010

Assing, Volker, 2010, On the Lathrobiina of Taiwan (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 60 (2), pp. 301-361 : 327-329

Lobrathium (Lobrathium) nigripenne sp. n. ( Figs 86-90 )

Type material:

Holotype ♂: " Taiwan - Chiayi Co., Alishan, Road 129, km 15.5, after Tanaigu Track , 600 m, leaf litter, 13.IV.2009, leg. Vít [7] / Holotypus ♂ Lobrathium nigripenne sp. n., det. V. Assing 2009 " (cAss).

Description:

Body length 5.7 mm. Coloration: body blackish; legs yellowish brown, with the profemora blackish-brown; antennae dark-brown.

Head 1.08 times as long as wide, widest across eyes ( Fig. 86 ); lateral contours between posterior margin of eyes and neck convex, posterior angles obsolete; dorsal surface with coarse and moderately dense punctation; interstices glossy, without microsculpture; eyes large and bulging, slightly more than half the length of postocular region from posterior margin of eyes to neck in dorsal view. Antenna slender; antennomeres II and III of subequal length and approximately twice as long as wide; IV-VI approximately 1.5 times as long as wide; X weakly oblong.

Pronotum 1.37 times as long as wide and 0.96 times as wide as head ( Fig. 86 ); lateral margins weakly and regularly convex in dorsal view; punctation similar to that of head; interstices without microsculpture.

Elytra approximately as long as pronotum ( Fig. 86 ); punctation very coarse and arranged in more or less regular rows; interstices without microsculpture and glossy. Hind wings fully developed.

Abdomen with pronounced and coarsely punctate anterior impressions on tergites III-VI; punctation of remainder of tergal surfaces fine and moderately dense; interstices with very shallow microsculpture; posterior margin of tergite VII with palisade fringe.

♂: sternite VII with posterior margin broadly and moderately deeply concave in the middle, in posterior median area with impression, on either side of this impression with approximately seven peg-setae ( Fig. 87 ); tergite VIII with distinctly convex posterior margin; sternite VIII oblong, along the middle with oblong impression, this impression with numerous peg-setae, posterior excision concave, its depth approximately 1/10 the length of sternite ( Fig. 88 ); aedeagus with ventral process of distinctive morphology ( Figs 89-90 ).

♀: unknown.

Comparative notes:

The new species is readily distinguished from all its congeners by the morphology of the aedeagus, as well as by the shape and chaetotaxy of the male sternites VII and VIII. In addition, it is separated from other geographically close Lobrathium species , for which illustrations of the male sexual characters are unavailable, as follows:

In L. hongkongensehongkongense ( BERNHAUER, 1931) from Hong Kong, the elytra are of different coloration (blue metallic hue, with the posterior fourth reddish-yellow) ( BERNHAUER 1931).

In L. partitum (SHARP, 1874) , which has been recorded from China and Japan, the elytra are bicoloured with the anterior half bluish-black and the posterior half bright yellow (SHARP 1874).

In L. regulare ( SHARP, 1889) , which, too, has been reported from China and Japan, the antennae are of yellowish coloration, the lateral margins of the pronotum are straight, and the elytra are shorter than the pronotum ( SHARP 1889).

In L. rotundiceps ( KOCH, 1939) , whose description is based on a single female from northwestern China, the coloration of the body is reddish-brown, the elytra are reddish at the suture and at the base, the head is of suborbicular shape, and the lateral margins of the pronotum are sinuate in the middle in dorsal view ( KOCH 1939).

For illustrations of the the male secondary sexual characters and the aedeagus of other Lobrathium species distributed in China and Japan see ZHENG (1988) and ITO (1995, 1996a, 1996b, 2007), respectively.

Etymology:

The specific epithet (Latin, adj.) refers to the uniformly blackish elytra, one of the characters distinguishing this species from similar congeners distributed in Taiwan.

Distribution and natural history:

The type locality is situated in the Alishan mountain range , Chiai Hsien, central Taiwan, not far from the type locality of Lathrobium alishanum . The holotype was sifted from leaf litter at an altitude of 600 m.

Figures

Figs 86-96: Lobrathium nigripenne sp. n. (86-90) and L. sibynium ZHENG (91-96): forebody (86); male sternite VII (87, 91); male sternite VIII (88, 92); aedeagus in lateral view (89, 93), aedeagus in ventral view (90); ventral process of aedeagus in ventral view (94); female tergite VIII (95); female sternite VIII (96). Scale bars: 86: 1.0 mm; 87-96: 0.5 mm.